From what I could gather from the article it's a really stupid ill-thought out law and damages the whole internet in Australia for the benefit of few news companies.
There's a major issue here because as a search company you could wake up one day to find that a single person has decided your revenue and expenditure has changed drastically. Even if you believe the spirit of this law is good, the way this is written is downright dangerous.
[0] https://www.accc.gov.au/system/files/Exposure%20Draft%20Bill...
In the meantime, Google is “experimenting” with leaving out Australian media entirely which on one hand is good (starving Murdoch of oxygen) but on the other hand is terrible (starving everyone of oxygen).
Google can just withdraw their business presence from Australia but continue to provide search.
If after that Australia wants to block Google like China that's on them.
If they served it out of Singapore or some other place in the region speeds would still be decent.
As for resources on such treaties, visit the OECD website and you'll be inundated with the model treaties that form the basis of the actual treaties between countries. (Some treaties involve many parties, most are between two nations.) Since you're not paying me, I will simply point out that under America's tax treaty with Australia, the Technical Explanation would note that providing services to another country's citizens is an activity covered by the treaty, and Australia's tax office has plenty of documentation saying the same.
Australia would be more than welcome to do the same.
(But hee hee, we secretly know their citizens would protest if they set up a national firewall.)
And a plethora of marketing businesses will go batshit on the government if they force Adwords out of Australia. Adwords is a huge part of the industry. We're going to see this sector struggle for a while if they need to re-adjust.
All financial transactions would take place outside Australia, Google wouldn't need a legal entity there.